How do you simplify 12a(a2+b)5b(b2+a)+9b(b2+a)3a(a2+b)?

1 Answer
Sep 20, 2017

9a3+13ab+4b3

Explanation:

Step one : Expand the brackets

12a(a2+b)5b(b2+a)+9b(b2+a)3a(a2+b)=

(12a)(a2)+(12a)(b)(5b)(b2)+(5b)(a)+(9b)(b2)+(9b)(a)(3a)(a2)+(3a)(b)=
which gives us

12a3+12ab5b35ab+9b3+9ab3a33ab

Step two : Collect like terms

  1. 12a35b35ab+9b3+9ab3a33ab=9a35b35ab+9b3+9ab3ab
  2. 9a3+12ab5b35ab+9b3+9ab3ab=9a3+13ab5b3+9b3
  3. 9a3+13ab5b3+9b3=9a3+13ab+4b3

Answer:
9a3+13ab+4b3